Mohtashemi studied in the holy city of Najaf Iraq, where he spent considerable time with his mentor the Ayatollah Khomeini. After the revolution he served as Iran’s ambassador to Syria and later became Iran’s Minister of the Interior. While ambassador to Syria, he is thought to have played a “pivotal role” in the creation of the Lebanese radical Shia organization Hezbollah, working “within the framework of the Department for Islamic Liberation Movements” run by the Iranian Pasdaran.

Mohtashemi actively supervised Hezbollah’s creation, merging into it existing radical Shi’ite movements: the Lebanese al-Dawa; the Association of Muslim Students; Al-Amal al-Islamiyya. In 1986, when the Office of Islamic Liberation was reassigned to Iran’s Ministry of Foreign Affairs, and his close supervision of Hezbollah was cut short. He is also described as making “liberal” use of the diplomatic pouch as Ambassador, bringing in “crates” of material from Iran.

In 1984, tragedy struck, when after the Beirut bombings, Mohtashemi received a parcel containing a book on Shia holy places. As he opened the package, it detonated, blowing off his hand and severely wounding him. Mohtashami was medevaced to Europe and survived the blast to continue his work. The identity of the perpetrators of the attack is unknown.

In 1989 the new Iranian president Akbar Hashemi Rafsanjani ousted Mohtashemi from the Lebanon desk of the Iranian Ministry of Foreign Affairs, replacing him with Rafsanjani’s brother Mahmud Hashemi. This was seen as an indication of Iran’s downgrading of its support for Hezbollah and for a revolutionary foreign policy in general.